Has USA hit its final frontier in human space exploration?

Still hoping for that Jetsons future?

Ruh-roh, as the Jetsons’ dog, Astro, might put it.

Just six years ago, President Bush laid out a vision of space exploration that harked back to NASA’s halcyon days built on astronauts as explorers. Bush wanted to sling them from low Earth orbit to a base on the moon and then, perhaps, on to a first manned landing on another planet, Mars.

But that was before huge federal deficits arrived, public support failed to show, and unmanned explorers scored successes — namely the Hubble telescope and Mars rovers Spirit and Opportunity, which are still sending back signals years after they were expected to expire.

So as we look to the next decade, what sort of human space exploration will we see?

“We are on a path that will not lead to a useful, safe human exploration program,” former Lockheed Martin chief Norman Augustine said when he testified to Congress in September about the blue-ribbon space exploration panel he chaired. “The primary reason is the mismatch between the tasks to be performed and the funds that are available to support those tasks.”

But NASA’s guardians say it’s premature to end the role of the astronaut.

“I do not see this president being the president who presides over the end of human spaceflight,” said NASA chief Charles Bolden, a former space shuttle pilot, when he spoke Jan. 5 at the American Astronomical Society meeting here. In the speech, Bolden said his agency would stress missions — small ones — with other nations as partners and look to new technologies, not the big chemical rockets of the past, to propel missions.